This invention relates generally to an electromagnetic wrap spring clutch. More particularly, the present invention relates to an electromagnetic wrap spring clutch wherein a clutch body assembly is housed within a field assembly having a unique bracket design.
Electromagnetic wrap spring clutches are well known. Such a clutch is disclosed in Gallo, U.S. Pat. No. 4,321,992, which is incorporated herein by reference. However, the clutch disclosed in Gallo has the disadvantage that its field assembly is formed as a round body, which results in material waste and long processing time during its manufacture.
This disadvantage was overcome in part by Ohsawa, U.S. Pat. No. 4,846,324. Ohsawa teaches that the round body field assembly may be replaced by a field assembly formed by two separate pieces: a bracket and a yoke. In another prior art clutch disclosed in Ohsawa U.S. Pat. No. 5,024,311, a U-shaped bracket for supporting the clutch assembly is provided. The shaft of the clutch is inserted through two facing walls in the bracket. However, due to the configuration, the resulting magnetic circuit is inefficient causing inferior performance. It would, therefore, be desirable to have a clutch with a field assembly made from a single-piece or unitary bracket which is more efficient than prior clutch assemblies to enhance overall clutch performance.